The Hounds of Hell
by Darkly Dreaming
Summary: Sherlock fakes his death and flees to America, where he encounters the Winchesters and learns of the Supernatural. When he returns to London 2 years later, he has an opportunity to put his newfound knowlege to use when he makes a deal for John's life.
1. Chapter 1

A/N: Sonofagun I am on a ROLL this week. I've finished 3 works-in-progress just since Thanksgiving. I started this almost two years ago and I've just finished it. I hope you guys like this one, cuz I had a fucking _ball_ writing it.

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><p>Sherlock had been in hiding for almost a year when he first started believing in the supernatural.<p>

After his 'death' he had flown to America to find Irene. Only to find her truly dead. She had been shredded to ribbons by enormous animal claws - in her apartment in the middle of the city. He arrived a couple of hours after she had been found. Apparently he looked suspicious enough for the authorities - that Sherlock could easily tell weren't really authorities at all - to pull him aside and question him.

Sherlock had called them out immediately and demanded to know what actually happened. With a few more condescending remarks and a jab at the shorter one's ego he got his answer: Hellhounds. A day of research and another of secretly following the brothers - for they were brothers, he could tell, even if they didn't look much alike - Sherlock discovered that Irene had made a deal with a demon 10 years previous. What the deal was for was unclear, but Sherlock thought he had an idea.

A month later Sherlock and the Winchesters parted ways as good friends. The brothers knew about Sherlock's past consulting, as well as his faked death. He learned about how they got into hunting and many of the basics.

On the second anniversary of his 'death' he went to his gravesite to see if John still visited; he did. John told him he was getting married soon, that he wished Sherlock were there to see it. A moment of silence and he turned and walked away.

He had taken down Moriarty's henchmen. Surely two years was long enough for the hype to die down.

He followed John around a corner and came to a halt. His heart stopped at the sight.

John was on the ground and the car that hit him was speeding around the corner.

"JOHN!" Sherlock ran to his friend and rolled him onto his back. His eyes fluttered open. "Sherlo-" he coughed.

"No John, don't speak," Sherlock said, cradling John's bleeding head. His pulse was thready and breathing shallow. He was fading quickly. "John, hold on. I came back. I came back for you." Sherlock could hear a woman calling an ambulance.

John was declared dead upon arriving at the hospital.

That night Sherlock did something he never thought he would be desperate enough to do: He summoned a crossroads demon.

"Hello, Sherlock."

Sherlock's blood ran cold. He had heard that voice before. But it was impossible. Rather, it was the most improbable circumstance anyone could ever imagine.

He turned and his eyes confirmed what his ears had told him.

Jim Moriarty stood in the middle of the intersection dressed impeccably in his trademark Westwood.

"Surprised to see me?" he asked, a smirk on his lips. "I understand. I felt the same way when I heard you had faked your death and went to America." Jim took a few steps closer and held up a finger. "I was even more surprised to learn that you had befriended the infamous Winchesters and started hunting."

"Moriarty," Sherlock whispered.

"Yes." The demon's eyes flickered black then back to their familiar whiskey. "Crowley told me everything, Sherlock. And I've been watching you ever since. I know what you're here for. That's why I came, myself."

"Give John back to me," Sherlock muttered, voice shaking. "And you can have my soul in ten years."

Jim smiled a shark's grin and laughed. "Oh no, Sherlock. You weasled out of our last bargain. How do I know you won't try to get out of this one?"

Sherlock tried to swallow, but his throat was too dry. He was desperate. "Because I need John. Eight years."

Jim's smile never faded as he took a few more steps forward. "No wonder the Winchesters took a liking to you. You're just like them. Neither could live without the other. You know Dean made a deal for his little Sammy? Just like you are for John." Another step. "Dean got a year to live."

He was finally close enough to Sherlock that he had to look up at his face. "I'll do you one better. I'll give you two. Two more years with dear John. And then you're mine." He laid his hand on Sherlock's ever-present blue scarf and waited for an answer. He knew how desperate Sherlock was, and he knew he had his soul in the bag.

"_'Prepared to do what ordinary people won't do,'_" Sherlock whispered, quoting himself. "_'If you want me to shake hands with you in Hell...I shall not disappoint you.'_"

"Perfect." Jim clutched the scarf and tugged until Sherlock's lips crashed onto his.

Thirty minutes later Sherlock stood at the foot of John's bed and watched his eyes open. He smiled, barely holding in his tears of relief.

"Hello, John," he greeted. "It's good to see you again."

John felt groggy and his head hurt, but otherwise felt alright. He gazed at Sherlock as if he were a ghost - or an angel. "Am I dead? Did that car kill me? Is that why I'm seeing you?"

Sherlock's smile shook, but held. "No, John. You lost a bit of blood when your head hit the pavement, and you passed out, but otherwise you're fine. The Doctor's say it's quite a miracle."

~*DD*~*DD*~*DD*~

Almost two years later, nearly four years since meeting him, Dean got a call from Sherlock Holmes.

He and Sam were just celebrating a quick and easy kill. They didn't have many, so they tended to appreciate them. Dean was appropriately cheerful. "Hey, Sherly, haven't heard from you in a while. Must not be many monsters on that island o' yours, huh?"

_"Not as many as one would think, but there are some. Which is why I'm calling. Can you fly to London? I need your specific...assistance with a particularly troubling situation."_

"Well, we just finished up a case here, so we don't really have anything goin' on. As long as you're payin' for everything else we can get the transportation." By which he meant he'd have Cas fly them, 'cause Cas doesn't crash like planes do.

_"Very well. I suspect the situation will be resolved fairly quickly once you've arrived. I'll tell you more later."_

The call disconnected and Dean finished the last bite of his burger, then a drink of his beer to wash it down. "Pack it up, Sammy, we're goin to London tomorrow."

"Sherlock, huh?" he asked, having heard Dean's half of the call. "Did he say what he was hunting?"

Dean got up and threw the fast food wrappers in the trash. "Nah. Said he'd fill us in when we got there, but I got a feelin it's demonic. No one ever asks us to help with a routine haunting. It's always freakin demons, man." He closed his eyes and basically continued in the same voice, "Cas! Hey, whenever you're not busy we need a ride to Sherlock's place in London. Like tomorrow."

~*DD*~*DD*~*DD*~

He didn't know how they did it, but Sam and Dean were standing in Sherlock's apartment the next day with two backpacks each. Presumably one held clothing while the other had various hunting paraphernalia.

Suddenly a man in a trench coat appeared next to Dean. "The building is secure against demons. The car is outside."

"Sherlock," Dean greeted. "This is Castiel. He's an angel."

"Dean's afraid of flying so Cas flew us here," Sam smirked.

"Planes crash! Angels don't!"

"We didn't fly here," Cas corrected. "I used my power to transport us here. You would not be able to survive flying with me, as I would have to be in my true form."

"True form?" Sherlock probed.

Cas nodded. "Angels inhabit a vessel much like demons, but we require permission from our hosts. Some angels strive to return their vessels in better condition than before, while others who don't care for humanity simply don't bother." He paused, then added as an afterthought, "My true form is approximately the size of the Christler building."

"Interesting. Now to business. Have a seat." Sherlock leaned on the arm of his chair and crossed his ankles while the brothers and angel sat on the couch.

"What do you know of James Moriarty?" he asked them.

Sam and Dean shook their heads. They only knew that he was an enemy of Sherlock's, but Cas looked intrigued. "I have heard Crowley speak of him, but I admit I don't know much myself. He is a high level crossroads demon much like Crowley was before he declared himself King of Hell. It was said Moriarty was Crowley's second in command and took over as "King of the Crossroads."" His use of finger quotes amused Sam, Dean merely rolled his eyes.

Sherlock nodded. It made sense. "He was also my criminal equivalent before I knew he was a demon. I'm a consulting detective. I solve crimes other can't. He was a consulting criminal. People hired him to carry out their crimes for them. He's the person responsible for my faking my death.

"He's come back and I'm going after him. I would appreciate your help."

Dean stood from his somewhat awkward seat on the couch and cleared his throat.

"Awesome," he said, more for something to say than an actual sentiment. "But first things first. I can't work without food and sleep. I can't speak for these guys, but there's somethin' about bein zapped halfway across the world that leaves me starving."

That night Dean slept in John's old room, Sam took Sherlock's, and Cas watched them, invisible so as to not make them uncomfortable. Sherlock stayed in the sitting room and played his violin softly. The song was inspired by John, written for him, really, but he never mentioned it, only ever played it as background music for thinking.

And he planned.


	2. Chapter 2

The next morning Dean made breakfast. "No offense, but I don't trust the British with food." They quickly ate and piled into the Impala, Sherlock in the front and Sam and Cas in the back. Sherlock gave Dean directions to a warehouse near the edge of the city. He only drove in the wrong lane twice.

They arrived at the warehouse shortly after noon. Dean had the knife, Sam the Colt, and Cas his angel blade. Sherlock had the knowledge that John was safe spending the day with Mary.

Every sigil, sign, spell, and trap they could collectively think of went on every surface of the building. They weren't taking any chances. In the center they summoned Moriarty.

They didn't have to wait long.

"Hello, Sherlock."

The four quickly turned around to find Jim behind them, hands in his pockets, smirking as if he had already won. "I see you brought an audience." He gestured to the Winchesters.

"They are only here to watch, aren't they Sherlock?" He swaggered forward until he was in arm's reach. "'Cause I know you'd never risk their lives just to save your own."

Two more steps, two more words. "Would. You?" So close Sherlock could smell the sulfur radiating off him in waves. How he'd not noticed it before was a mystery Sherlock could never solve.

Sherlock kept his head up and only glanced at Moriarty once as he spoke. "They are here for...support," he said slowly, keeping Moriarty's focus on him for as long as possible. "John knows nothing of this world and they insisted I not...what was the phrase? 'Go alone?'"

"Ah, yes," Moriarty raised his voice. "The infamous Winchesters and their bleeding hearts." He looked at Dean and shrugged. "Too bad everyone they love ends up dead." His eyes met Sherlock's again and he smirked. "Too bad."

A subtle flick of his wrist, almost hidden in his pocket, was all the warning they got before all hell broke loose.

The doors burst open and a violent wind came rushing past. When they looked back at Moriarty he held a bound and gagged John Watson. He was confused and slightly afraid until he saw Sherlock and Moriarty. At that point he didn't know quite what to think or feel, and thus kept his face neutral, not showing fear, but also not showing confidence or confusion.

Castiel was the first to react. He tried getting the drop on Moriarty, but the wind that blew through the door had brought with it leaves and sticks from the woods nearby that scratched away just enough of the devil's trap on the floor for him to blink away just in time. He reappeared holding John by the bicep and pressed a knife to John's throat.

"Now now, Sherlock," he grinned. "What did I tell you, dear? If you try to renege on our deal I kill both of you."

"Oh, but _Jim_," Sherlock smiled, a mockery of pleasantry painted on his face. "I have done no such thing. So far it has been nothing more than an angel trying to take advantage of a distracted demon. Obviously it did not work, but I, myself, had no actual hand in it. Therefore, no deal broken." He knew what he was doing: prolonging the inevitable. But as long as he could, he would prolong it. Perhaps, if they were very very lucky, the rest of them may get out of this relatively unscathed. If they could take down Moriarty, fantastic, but they still had to worry about the Hellhounds waiting just outside.

Sam, still behind Moriarty and John, held up the Colt and aimed it straight at the demon's head and fired.

Either Moriarty didn't think anyone would actually risk John's life, or he forgot about Sam standing behind him with the Colt, but the shot hit. Unfortunately, he didn't drop immediately. He had just enough time to thrust a blade into John's spine.

Before Sherlock could even yell, Castiel was on him, pushing away Moriarty's dead vessel and healing John's wound. As a kindness, Cas left him unconscious for the time being.

"He's healed, but let him lie," Castiel ground out. "We still have Hellhounds to deal with."

As if he had called them, the goopher dust and salt line broke and the Hellhounds bound in barking. As the one they were after, Sherlock could see them, but the other three were fighting blind. Castiel gave Sherlock an angel blade and he vaguely wondered where it came from if he already had one.

"How many?"

"Four," Sherlock replied. "One for each of us, I imagine. Sam, if that gun can kill a Hellhound there's one on your ten o'clock. Don't shoot yet. Dean, your one o'clock. Castiel, can you see them?"

"No, but I can sense them. Don't worry about me."

"Fair enough." His voice was starting to shake. He gripped the angel blade tighter and readied himself. Hopefully this worked. "NOW!"

Sam emptied the Colt into what he saw as empty air, but was rewarded by the sound of canine whining and the ground puddling in shadow.

Dean wished he had the Colt instead of Ruby's tiny pigsticker, but it was better than nothing and he ran in the direction Sherlock called but was knocked down by a very familiar and heavy force. He smelled the Hellhound's foul breath, heard the deep growling, and plunged the knife into the hound's gut, gouging as much as he possibly could.

Castiel flared his grace a little and the remaining hounds were thrown into sharp shadows and drawing their ire his way, which gave Sherlock the time needed to run up and stab the damned thing trying to drag him down. Castiel disappeared and reappeared beside the last one and stabbed it through the head.

"That was a hell of a lot easier than I hoped," Dean panted, covered in dark, sticky liquid - Hellhound blood.

Sherlock ignored everyone and ran straight for John. Castiel came up beside him.

"I was able to heal him. He'll be fine. If you like, I could...erase his memories of this day, make him believe nothing had happened."

Sherlock thought about it. He thought about everything that had happened since his "death." Everything was different now. A whole new world had opened up for Sherlock to explore and he thought about exploring it without John.

"No," he said. "No, I will explain it to him. He needs to know. He...he would want to know."

"In that case, he will remain unconscious until you return home."

Sherlock put John in the middle of the back seat between him and Cas, while Sam took shotgun and Dean drove. He gave directions back to 221B from there.

They dragged him up the stairs, past a surprised Mrs. Hudson, and deposited him on his old bed. Mrs. Hudson brought up tea and promptly left them alone, adamant to have her answers, but unwilling to pester them right away.

The Winchesters said their farewells while John slept.

Dean shook Sherlock's hand. "I'm not gettin you outta any more deals, ya hear? That was it. But, if you need our help for anything else, you know how to get hold of us."

"Of course, Dean. Sam."

Sam smirked. "Don't hesitate. If we find out you died from something we could've helped with we'll seance your ass back here and kick it."

Sherlock ducked his head and smiled, not used to having so many people actually care about his well-being. When he looked up again, Cas was in front of him. They both stood up straight and shook hands.

"Mr. Holmes."

"Castiel," Sherlock returned. "Thank you."

Cas nodded. "You are welcome. The Winchesters' offer goes for myself as well. If you pray to me, and I am able, I will help."

Rustling noises were heard from John's room and Cas touched the Winchesters' foreheads and disappeared in a gust of wings.

Sherlock sighed and prepared himself for the conversation and likely fallout that were to come.

But at least they were both still alive.


End file.
